负载型粒子电极电催化氧化苯酚的研究

Electro-catalytic performance of the activated carbon supported metal oxide as particulate electrode for phenol oxidation

以颗粒活性炭(AC)为载体,分别采用氧化还原法和热分解法制备了炭载纳米MnO2、SnO2-Sb-Mn粒子电极,并通过X射线衍射(XRD)、扫描电镜(SEM)及电化学测试对其物相组成、微观形貌和电催化活性进行表征.结果表明,制备的MnO2晶粒主要以α-MnO2与δ-MnO2晶型聚团存在于AC孔隙边缘,SnO2-Sb-Mn活性组分则以固溶体形式分布于AC表面及孔隙内,两类晶体平均粒径分别为11.47,13.70nm,金属氧化物镀层可增加循环伏安曲线测试过程的伏安电荷量,提高粒子电极电催化活性.填充床苯酚模拟废水电催化降解实验表明,MnO2/AC与SnO2-Sb-Mn/AC填充床电极反应器出水苯酚及COD去除率均高于AC填充床,电流效率增大而能耗降低.在电流密度12.0m A/cm2和反应时间140min条件下,SnO2-Sb-Mn/AC粒子电极的苯酚及COD去除率分别为94.7%和90.4%,电流效率达62.7%,能耗为20.3k Wh/kg COD.

Granular activated carbon （AC） was used as substrate for fabricating of nano MnO2and SnO2-Sb-Mn loaded catalytic particulate electrodes with redox and thermal decomposition methods, respectively. The phase composition, micro-morphology and electrocatalytic activity of the newly prepared particles were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM） techniques as well as electrochemical test. The results showed that the as-prepared manganese oxide was mainly shaped in ct-MnO2and δ-MnO2, which fixed in AC pore edge. SnO2-Sb-Mn component exist as the solid solution distributed on the surface and in the pore structure of AC. The average size of the two crystal was 11.47 and 13.70nm. Metal oxide coatings could increase voltammetric charges during the cyclic voltammetry （CV） scanning process, and improve electrical catalytic activity of particle electrodes. Bulk electrolysis experiments in packed bed electrochemical reactor were conducted with simulated phenol wastewater. The experiments data displayed that the removal of phenol and COD concentration with MnOE/AC and SnO2-Sb-Mn/AC filling were better than that of virgin AC, higher current efficiency and lower energy consume would be realized. The removal ratio of phenol and COD on SnOE-Sb-Mn/AC particles was as high as 94.7%, 90.4% under 12mA/cm2current density during 140min purification, with concurrent ACE reached about 62.7% and gsp 20.3kWh/kgCOD.